need help: 1993 850 glt chugs on the road

mdpete3 · Post by **mdpete3** » 05 Sep 2008, 13:42

1993 volvo 850 glt my car chugs on the road .i think its the maf but not sure. i get the code for it 121. the car seems fine when i unplug the maf, then when i plug it back in it kills the engine. also not sure if this is related but the gas gauge,speedometer,tach and water temp gauge dont work. the low fuel light and service light are blinking thanks 150,000 miles

Post by **Ozark Lee** » 05 Sep 2008, 14:12

The 121 code points to a bad MAF or a bad connection to it.

The instrument cluster problems shouldn't be related to the MAF problem. For the instrument cluster use test port A-7 and put it through a self test.

This is done by pressing the button 3 times. The instrument cluster should then show the tank at half full, the temp gauge at the bottom edge of the red, the speedometer and tach should have the needles at the vertical (12:00) position.

If the cluster checks out OK read and then reset the codes in A-7. At the end of the day It sounds like wiring problems and you just have to go after it with a VOM.

...Lee

mdpete3 · Post by **mdpete3** » 05 Sep 2008, 14:15

the a-7 socket blinks the same as the service light

Post by **Ozark Lee** » 05 Sep 2008, 14:25

Are you saying that when you plug into socket A-7 the LED just blinks - even without pushing the button?

If so I am going to guess that your instrument cluster is bad. I see them on eBay all the time but I think I would change the odometer gears on any used one that you would install. It also gives you a chance to adjust the mileage to match yours so long as the replacement has fewer miles than your car.

...Lee

mdpete3 · Post by **mdpete3** » 05 Sep 2008, 14:42

yes a7 blinks without pushing the button. also is it allright to run the car with the maf unplugged or can you bypass it.

Post by **Ozark Lee** » 05 Sep 2008, 14:50

is it allright to run the car with the maf unplugged or can you bypass it.

Unplugging it puts the car into limp mode and it will run like crap and the mileage will be horrible. Running without it long term will fry your catalytic converter.

...Lee